• A patient with hyperviscosity syndrome was noted to have an abnormal liver radionuclide scan. Ultrasound and normalization of the liver scan after plasmapheresis confirmed the non-neoplastic nature of the patchy labeling defects. This case suggests a new cause for labeling abnormalities on liver radionuclide scans in patients with a syndrome where liver biopsies would be unusually hazardous. Possible mechanisms for this scintigraphic pattern in the hyperviscosity syndrome are briefly discussed.